Dam.



PATENTE) om 16, 1906. WK L. CHURCH.

DAM.

APPLICATION FILED PBB.G,1906.

yof Newton, in the count Fi 3 is a View similar to Fig. i

UNITED- errug@ SETTC.

no. seasoe.

Application filmt February 6, 1906. Serial No.

Speccaton of Letters Patent.

'Patented ot. i6,

To @Zhu/hom, rit 'may concern:

Be it known that i, WrLLrAM L. CHURCH, of Middlesex and State ofMassachusetts, rave invented cer tain new and useful Improvements inDams,

of which the following is a specification.

My invention relates to dams, it being especially directed to means forpreserving the foundations of such structures.

It is customary to provide dans; either with a verticnl face past whichthe water falls from the crest or with en inclined apron over and inContact with which it flows. in either ease the water strikes the bed ofthe stream in comparatively close proximity to the adjacent ede of theiioo'r or foundetion of the darn, was ring it away, undermining thestructure obviates this difficulty.

In the accompanying drawings, in which similar characters designate likeparte' throughout the several yiews, Figure l is e transverse verticalsection through a dem, showing one embodiment-of in invention. Fig. 2represents an elevation o the dem as seen from the downstream sidethereof. of a darn of and gradually .My invention di erent type.

Referring to Fi 1,' a shell darn is shown, having a floor or `oundationl() resting upon the lied of the stream end an upstream willi or deck11, extendin to a crest 12. At the downstream side of t re darn is an,apron 13, curved outwardly or eonveXedl-y from the edge a of the crestto a point af', i,`n,e'curv a-4 ture hein@ a proximately that given'tot' grav ity and t eliead of water above the een to the fiuid str am Spassing over it. T" een the points' and uji the apron is inci'ineddownwardly and outwardly on an approximately straight slope, and from toits termination b it is c'urved in a direction. reverse to the upperportion-that is, concev-4 edly. This lower portionis located at souledistance aliove the foundation. The reverse or concave curvature of theterminel portion ofthe apron is referably continued until the surfacethereof) which supports and guides the -fluid @stream is substantiallyhorizontal, es shown in Fig. ,1, Thereby, and also liecause of theheightof said terminal portion above the dani-foundation, the stream flowingover the apron is deflected and projected from the terminus thereof in edirection which carries it -direetly ewa from the downstream face of thedarn en half that of the crest and theminiinuin possi prevents ittermineting e portion. ioceteu. ietermede striking the hed of thestre-ani, eiseept 'et points so far distant from the. dani that theshock and. erosive action of the siiing Water cannot injure or underminethe iounf'ilations of the darnt The height of the terminus t of tl"above the nem-foundation is thet the latere-i projection of the that is,the diste-nee 'from the E point e, at which it strikes the hed-ismaximum, i have found that the ineen@ mum yproiection occurs when the ithe terminus b is half that of the crest dem above' the hedirorn which'it uccordingiy i prefer to locate the lei approxirnateiy midwayhemmen-these oi hase and crest.

liihen the terminal portion ci the apron is horizontal end is iocate eta height equal to ble iow of Wetter is passing, the Water strikes thebed at a distance equei to the entire height of the dem from the basethereof, friction being disregarded. W hen the head ofwater over the demis increased so as 'te increase the 'veic-city of iow over the crest,this distance is mede greater, as it is. also Then 'the eproneterininusis elevated oy con.d tinuinn' the concave curvature to e point 85ahovenc horizontal, es in Fig. The trated end 'eatery of the stream isthen eleve iength increased. @n the other hand, the stream rejection mayhe lessened hr" ing the evel of the apron-termi above specified. ordepressing :i e thereof.

Preferably the slope of the rectilinear pei-t of the apron snede 'tocoincide es neeriy possible 'with the path of the 'fuid der greatestnormal heedj ti eiinnnated as conipietely as possioie, whiie the sainetiinefhe spree-in is 'neus/d to ,tiowin contact with the apron' er itsentire sione. .i have shown 'this invention ir co r wit i e. sheii orceiluier dani, suoi v prior Letters Patent No. 768,717, granted Auvust3G, 1904, in which, the deck, crest, enc. apron are supported by Wellsi4 inter-` inciinetron i. A dem coinpr'sing a crest, .s epron removedfrom the base.

2 A dsl-n1 having en apron terminating in 5 a. eonmivedly-curved portionlocated at a height intermediate the hase and crest of the dem, such todeflect and owing thereover fore striking xo dation is built.

3. A dem havin the he project the Water wholly free ofthe darn, be l don which the darn-founi g an apron terminating in a, .oonevedlyurvedportion located at e height intermediate the hase and crest of the dani,such as to deflect land project the Water a. distance not less than fromthe founda- 15 flowing thereover the total height of the dam tionthereofhefore striking the hed on which the foimdotion is 4. A `damhovin built.

e base approxinmtel g an apron terminating at half of the darn, andhaving its and constructed to desurface adjacent the terminusinolinednway the dem lto a, point from the slope of lthe apron,Whereby'water flowing over the darn is deflected away therefrom, sindcaused to strike the bed of the overflow wholly clear of thedam-foundation.

5. A dam having au apron terminatin at a. heightfrom the baseapproximately ialf that of the crest of the dani, and having its slopeadjacent thel terminuseurved into a. substantially horizontal direction7whereby water liowing over the dem is deleoted, and t caused to striketho bed of the overflow at a f distance not less than the total heightof the l duin from the duin-foundation. i in testimony whereof I haveaffixed my il signature in presence of two witnesses. i" WlLIilAhl li.CHURCH. f ritnossosz y HOWARD IJ. ConUnN, C. H. EGLEE.

